27511

Appears in sequences

• Strong pseudoprimes to base 42.at n=17A020268
• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 33 ones.at n=4A031801
• From the game of Quod: number of "squares" on an n X n array of points with the four corner points deleted.at n=22A124479
• Numbers k such that the sum of the Carmichael lambda functions of the divisors is a proper divisor of k.at n=20A131492
• Numbers k such that 2^(2k-1) == 2 (mod 2k) and such that 2^(k-1) != 1 (mod k).at n=40A176033
• Number of (n+2) X 6 0..1 matrices with each 3 X 3 subblock idempotent.at n=16A224555
• Odd numbers k such that A064989(k) is in A340151.at n=37A340091
• Odd composite integers m such that A001906(m-J(m,5)) == 0 (mod m) and gcd(m,5)=1, where J(m,5) is the Jacobi symbol.at n=42A340097